That's What Makes Us Human
by Unoriginality
Summary: Bucky finally honors his promise to let Bruce take his blood to analyze is DNA for potential oncoming disasters that Hydra's drugs might've caused. It's not an easy thing to do, nor are the answers easy to take. (Warning for mangled Marvel science that may offend actual biology students. A BTWWL fic.)


"Come on," Steve said. "You promised Bruce, and you've been putting it off for three weeks."

Bucky didn't move from his spot on the couch, hiding behind his tablet. "If you want a needle jammed in you so badly, you go all by yourself."

Steve stood over him, and Bucky had to hunch down in his seat and lift his tablet up to stop being able to see the stern look Steve was giving him. Steve reached out and yanked Bucky's tablet out of his hands, ignoring his protests. "Come on, you promised."

Bucky did his best to not look like a sulking teenager, but he had a feeling he didn't succeed. "I don't wanna."

Okay, that didn't help much.

Steve raised an eyebrow at him, "Bucky. You. Promised."

And Bucky didn't break promises. He held his scowl for a few more heartbeats, hoping it'd hide that he was actually afraid of keeping that promise, then let out a huff. "Fine." He got up. "You call him, I'll get my damn socks and boots, and we'll go get the integrity of our veins violated so a scientist can do sciencey things with our blood, because _that_ has never led to anything bad."

Steve grabbed the back of his neck in a reassuring gesture. "Relax. This is Bruce. He's not going to do anything to hurt either of us. He's just making sure there aren't going to be any unwanted side effects of what was used on us. He needs a few blood samples for that. That's all." Then he gave Bucky a mock-stern look. "Besides, I don't want to hear this scientist nonsense from you, Mister Chemical Engineer."

"Engineer," Bucky said in a rather pathetic attempt at pushing aside the main subject. "I'm not a scientist."

"Remember the 'chemical' part," Steve said. "You're a scientist, deal with it. Now come on, you promised."

"So you keep saying," Bucky said, feeling defeated. "Let me go get my socks and boots on, then we can go. Might wanna let him know we're on our way."

Steve shooed him off, saying he'd contact Bruce, so without any stalling techniques, Bucky retreated to his room to pull on his socks. It wasn't that he didn't want to know what Bruce might find, didn't want to know there wouldn't be any adverse effects that hadn't shown up yet from the chemicals Hydra pumped him with.

It was the idea of a needle coming near him again. It was the idea that while Bruce would never experiment on him based on what he found, every scientist that came before him _had._ He liked Bruce, but that was putting a heavy load of trust on him that Bucky wasn't entirely sure he could hand over.

But, he'd promised, as Steve pointed out, and Bucky didn't like breaking promises. So on went his socks, and back out of his room and down the hall to the coat closet. He grabbed his boots and yanked them on. Steve was waiting patiently for him, made sure Bucky wasn't armed- what, did he think that Bucky would shoot Bruce or something?- and then headed out, Bucky in tow.

Bucky spent the entire trip in the elevator to the medlab trying to squash the butterflies tangling up in his stomach. _It's Bruce_, he kept reminding himself. _Bruce isn't going to do anything to you, or with your blood. Settle down._

The receptionist in the front lobby of the med center told them to head on back to Bruce's private lab, he'd be with them shortly. Bruce must've been with a patient when Steve contacted him. Grateful for the fact that Steve could navigate his way through any place, Bucky let Steve lead them back through the secured doors that Tony had shown them through shortly before Christmas, and in further to the lab.

The lab wasn't empty when they got there; Tony was seated on Bruce's lab stool, rolling around the room like a small child. "Hey guys!" he said when they entered, zooming by the front door. He turned and pushed himself back the other way, passing by them again. "Finally came in for that blood sample?"

They both remained silent, watching Tony make another pass, before Bucky was able to answer with a "something like that" that was rather vague, his brain more focusing on the fact that Tony Stark, a forty-something year old man, was flying around a doctor's lab on a wheeled chair like he was eight.

Tony came to a stop by them, and motioned them in. "Come on. Bruce takes samples back here in the phlebotomy lab. We've got everything set up in there that he needs." He proceed to push himself backwards towards the lab.

Bucky followed him with Steve. "Aren't you a little old to be doing that?"

"Nope," Tony said, entirely too quickly. "You're never too old to have fun. You might relax a little if you tried it."

"I'll relax when the needles go away," Bucky said.

Tony slowed to a stop by a doorway that led into what looked like another large lab with a medical chair designed to make drawing blood from a patient easier that made Bucky's stomach do some unhappy flip-flops and resurrect those butterflies he'd managed to kill earlier. He declined to enter just yet.

"Can't say that I blame you for the fear, but you got nothing to worry about," Tony said. "It's a quick poke, take some blood, then done. I'll even have him give you a lollipop for behaving."

Bucky shot him a dirty look. "I'm not a kid anymore, Tony, I don't need candy as a reward for playing nice with the doctor." Then he lowered his gaze pointedly at the stool. "You, on the other hand, I would question."

"Told you, never too old to have fun," Tony said. "So what finally dragged you down?"

"Steve stole my tablet and reminded me that I promised," Bucky said, sulking in Steve's general direction.

Steve put a hand on his flesh shoulder. "He's been putting it off. Bad old memories."

"Not surprised, Bruce probably won't hold it against him. He came in as he promised, after all," Tony said. Then he studied Bucky. "Relax. Bruce is the best, he won't hurt you."

"I know that," Bucky snapped, then drew in a steadying breath, feeling guilty about being so defensive. "Sorry."

Tony held up his hands as if in surrender. "No hard feelings. Things just sink in better when you hear them multiple times. Helps when it's from different sources, too."

Bruce entered before Bucky could get a chance to answer. "Sorry I made you wait," he said. "There was an employee who came in with her sick child. She claims Urgent Care wouldn't take her insurance, and her doctor couldn't get her son in until next week." He shook his head. "I can't believe that insurance offered by this company doesn't cover Urgent Care."

Tony scowled. "Neither can I. I'll send a message along to the employee benefits department, have them look into that."

"Her name is in the records for the afternoon," Bruce said.

Tony spun on the chair once. "So our old guy friends are here to give blood, like the saints they are," he said, motioning to Steve and Bucky.

Bruce's lips twitched into a wry smile. "I couldn't tell." He eyed Bucky. "And one of them is nervous, I see."

Bucky startled a bit, looking around, then back at Bruce. "How you can tell? I was just standing here."

"You're jumpy, for one," Bruce said, then motioned to Bucky's left hand. "And you're doing the finger tapping thing."

Slowly, feeling like a caught child, he glanced down at his left hand, his index finger tapping against his thigh compulsively. He gave it a betrayed look, then crossed his arms to keep from doing it again. "Does _everybody_ know about that?" he demanded, still defensive. Bruce being there meant that the needle was imminent.

Bruce smiled. "I don't know who else knows or why, but I've asked Steve for signs of stress in you. I'm your doctor, I need to know these things."

Suddenly the center of attention and not liking it, Bucky made a childish face. "I don't like needles, that's all. Name someone who does."

"I could," Bruce said, "but I suspect that's a different type of liking. You're right, few people enjoy needles for medical reasons." Then he looked at Tony. "You're first, then we'll let Steve and Bucky decide who goes next."

"Why is Tony having his blood drawn?" Steve asked, looking between Bruce and Tony.

Bruce gestured for them to follow him into the phlebotomy lab, where that awful chair was. "He's my control subject," he explained. "Despite his high intelligence, he's still just a normal human, with normal human DNA. If there's been any mutations in your respective genetic codes, I'll be able to compare them to his to try to isolate what changes are doing what."

Tony wheeled himself up to the door of the lab before getting up, pushing the stool slightly out of the way. He flopped into the chair. "Hit me, Doc."

Steve stepped in behind him, leaning back against the wall near Tony. Bucky elected to remain in the doorway, easy to get away if he had to. He knew he wasn't being fair to Bruce, and he was upset with himself for letting his nerves show in front of anyone but Steve, but there were just some things he hadn't had a chance to get over yet.

Bucky had to turn his head and not watch as Bruce drew some blood from Tony, and it felt like it took forever before Bruce spoke up, declaring Tony done. Bucky looked back in to see Bruce covering a cotton ball with a bandaid over Tony's new needle hole.

Bruce looked between Steve and Bucky. "I'm gentle, I promise. So who's next?"

Steve looked at Bucky, expecting an answer, and Bucky just shook his head. Steve took the hint, and stepped around Tony. "I am."

Bucky turned away again, stomping down on the desire to intervene, his anxiety over a scientist drawing blood mixing with his overprotective streak to create an ugly tight feeling in his chest and cause his right hand to ball into a fist and shake. His left hand stayed still by sheer force of will.

Tony's voice nearly made him jump, made his heart accelerate as he was pulled from his sorry attempts at keeping himself under control. "Easy," Tony said, voice low. "Bruce isn't going to do anything bad with that blood. Cap's safe."

Bucky drew in a deep breath, forced himself to hold it as he closed his eyes, then let it go, slowly. It didn't help much, but it took the edge off. "I know. It's just been a long time since I've had a good interaction with a medical scientist."

"You were willing to take that Methylphenidate-C Bruce made for you," Tony pointed out.

At first, Bucky didn't answer, brow furrowed as he tried to figure out the best explanation that made sense beyond his currently addled brain. "Pills don't have long-lasting effects, they weren't used much."

Tony nodded once in understanding. "But the long term stuff, that was all injected with needles?"

That time, Bucky didn't answer at all, glanced into the phlebotomy lab when Bruce declared Steve successfully poked and drained.

Bruce was holding a cotton ball over the injection site, then lifted it, studying where the needle had been. "Already not bleeding. Can't say I'm surprised, with your healing factor."

Steve rolled down his shirt sleeve. "Yeah, when the scientists with the SSR took a sample, they didn't even bother with the cotton ball."

Bruce tossed the cotton ball away and put the three small vials of Steve's blood into a small box of sorts that had three sections with small, round slots for the vials of blood. The far left and middle sections were filled now. That left the far right for Bucky's blood samples.

He balked, staring at the chair that Steve had just vacated. He heard 'your turn' from someone, saw Bruce motion to the chair, but his feet remained rooted to the spot, his legs refused to move. He felt his right hand begin to shake again.

"I got an idea," Bruce said. "Bucky? Bucky, can you hear me?"

"I hear you," he said, voice hollow, lips barely moving. But he managed to say it.

"Good. Come on, let's go out here. I have a nice stainless steel counter you can sit on. We won't use the chair."

Even with the lingering promise of a needle and a blood draw, he felt relief crash on his head at the prospect of not having to sit in a chair like that. His hand stilled, and he nodded, licking his lips and swallowing hard, trying to get rid of the dry feeling.

"Steve, why don't you take him over there, get him comfortable. I'll follow with the blood draw supplies," Bruce said. He was studying Bucky over his glasses.

If it wasn't for the fact that the attack that the whole mess was causing hadn't fully abated, Bucky might've been of sound mind enough to feel humiliated at the spectacle he was making of himself. But with the blood still needed drawn, that silent scream in his head was still there, and he had to be prodded by Steve over to the counter. He obeyed the command to hop up and sit on it, and waited, taking in several deep and unsteady breaths.

He heard rather than saw Bruce set down his supplies on the counter next to him, and he spared just enough of a glance to see the container with the blood vials, and five empty vials. The container held three each from Tony and Steve.

"Why five?" His voice sounded almost hysterical in his ears.

Bruce looked up at him, seeming to make a point of eye contact. "If I have more tests I need to run than what three would give me, I won't have to ask you to go through this again."

The eye contact was different from what the other scientists had done. They hadn't bothered doing anything to treat him as anything but an experiment, not a human with fears or even misgivings about what was being done to him. That helped. A tiny bit, but it helped.

Obediently, Bucky followed the instruction to roll up his sleeve, to hold his arm down straight. He closed his eyes as the rubber band was tied around his upper arm, just above the crook of his elbow. He gripped the edge of the counter as the doctor's gloved fingers tapped along his arm for a vein. From somewhere down the tunnel, he heard the screeching of metal bending.

There was talking, then the band was removed. "Bucky?" He couldn't respond, mouth too dry, chest too constricted, stomach too twisted into knots. His fists were clenching. A hand touched his left thigh and he jerked his arm out, smacking away whoever'd touched him. Damn the consequences.

Steve stumbled back a few steps, but didn't fall. "Bucky, it's okay. It's just me."

He stared at Steve, pulled just enough back into his own proper brain to realize that one- he'd just hit Steve, and two- both Bruce and Tony were watching him patiently, annoyingly so. Bruce was still holding the rubber band that he'd untied, his hands in a pair of blue sterile gloves.

Bucky hunched over, his hands tangling in his hair in frustration, trying to calm his breathing, pulling on every technique he knew as a sniper to bring his heart rate down to a sane level. "I'm fine," he said. "I'm fine."

His hands were shaking.

He felt Steve place a light hand on his thigh, and just barely saw his other hand move to rest on Bucky's metal shoulder. "It's okay," Steve said. "You're not back there."

"Steve, I think we might need medicine intervention with that severe of a panic attack," Bruce said.

"I'm fine, I'm-" Bucky took in a deep breath, dropping his hands into his lap. He glanced at Steve, and paused, hesitated, then looked down at the counter. The spot where he'd been gripping it with his left hand was warped and twisted from the force of his hold. The damage looked worse than it had out of the corner of his eye. He sat up a bit, tilting his head back to look at the ceiling and not at them. "I'm sorry."

"It's okay," Bruce said, pulling off his gloves. "Tony, get me a glass of water, please?" While Tony walked past them to the sink on the other side of the room, Bruce adjusted his glasses, holding eye contact with Bucky again. "I know my MD doesn't really cover psychiatry, but I'd have to be pretty blind to not see how much this is upsetting you. You can back out now, and we'll find another way to look for any potential damage by those chemicals, or I can give you a sedative."

Bucky swallowed against the dry mouth feeling again. "I thought normal medicines wouldn't work on me."

"Not for long term, certainly," Bruce said. "I can give you a milligram of Ativan. It's a fast-acting sedative, usually used to treat panic attacks and general anxiety disorders. It won't stay in your system long, but it'll last long enough for me to get the blood draw done. You can take a pill, we'll give it a minute to kick in, and you'll know when it does. When you get nice and relaxed, I'll do the draw, put the needle in the sharps container, you won't even know it was there."

Bucky's shoulders slumped, and he ran a hand through his hair, hand unsteady, before having to swallow one more time and then nodding. "All right. Yeah, we'll try that, I guess. Sorry, I-"

"It's okay," Bruce said. "You don't need to explain. We've all been there to one extent or another, we all have our triggers." Then he smiled. "You're reacting better than I do when I get that upset."

Tony rejoined them, holding the requested glass of water. "Your path of destruction generally includes more than a mangled lab counter, that's for sure."

Bruce didn't say anything to that, just took the glass and set it on the counter next to his phlebotomy supplies. He looked at Tony. "I hate to send you on an errand, but I'm going to write a prescription for that Ativan pill, I need you to go get it. I think it'd be best if I stay to monitor him, and Steve's going to be better at calming him down than you will."

"Understood," Tony said, glancing up at Bucky. "You gonna be okay if you lose sight of my charming self for a few minutes?"

"Oh for god's sake, I'm not a child," Bucky said, trying to sound far calmer than he actually was. All he sounded like was someone on the verge of tears. He felt like he was on the verge of tears, a mixture of anxiety and embarrassment making his eyes sting. He concentrated on breathing.

"We know, Buck," Steve said. "But you know it helps to be talked to. You've talked me through a couple episodes, too. That's all we're doing for you."

If it wasn't for the fact that he _had_ finally seen Steve having an episode of his own, Bucky might've felt even worse about panicking in front of Bruce and Tony. He wasn't even fully comfortable with them happening in front of just Steve. He folded his arms across his stomach, trying to make it unclench while he waited for Tony to get back with that medicine.

"Bucky?" Once again, Bruce made sure to make and maintain eye contact once Bucky had turned his head to look at him. "Mind if I take your pulse? I'm not going to do anything else, I just want to establish where you're at before I give you that Ativan."

Bucky didn't vocalize an answer, but held out his wrist for Bruce. Bruce gently took his wrist, fingers over his pulse, eyes on his own watch. After about fifteen seconds, he nodded to himself and let go of Bucky's wrist. "Thank you."

"How bad?"

"Hm?" Bruce blinked a couple times at him, then smiled. "Almost ninety. Normal range for a normal adult, but with your cardiovascular condition, you should be closer to forty. So a little elevated. I imagine it was worse a minute ago."

Bucky made a noise of acknowledgement, returning his arm to its previous position of folded across his stomach. He was getting so sick of these episodes. They weren't as often as they had been, been getting fewer and farther between over the last two years, and he logically knew that he'd probably never fully get away from them, not with how much his head had been messed with. But they were tiring.

Tony returned carrying a small, almost opaque, orange bottle. "Here you are, Doc, one Ativan pill, one milligram."

Bruce took the bottle from him. "Thanks." He turned to Bucky. "I had Tony get that water for you to take this with."

Bucky looked down at the dixie cup on the counter beside him, studying it a moment before he got his arms to cooperate with him enough to grab it with one hand, and take the pill from Bruce once it was offered with his other.

He told the voice in his head scolding him for needing to be sedated at the doctor's for a simple blood draw to shut the fuck up and took the pill, emptying the tiny cup of water. He glanced around for a trash for the cup.

Tony took the cup from him. "I got this," he said, and walked over to the trash by the sink. He rejoined them, crossing his arms and looking at Bruce. "So how long does it take to kick in?"

Bruce glanced over at him. "Depends. I have a feeling a five minutes might be generous with him. It'll probably take effect faster than that."

"You sure it'll last long enough, if it goes that fast through his system?"

Bruce shook his head. "I'm not sure of anything when it comes to medicating these two. But it doesn't take more than two minutes to do a blood draw, assuming I find a working vein first shot, and it should last at least that long."

"I can hear you, you know," Bucky said, still feeling somewhat irritable, but he was slowly relaxing, tension draining out of him.

"We know," Bruce said. "We weren't trying to talk about you like you weren't." Bruce started asking him a series of questions, none of which made sense to him, but he answered them dutifully, until a few minutes had passed. Bruce went silent, studying him. At Bucky's 'what?', Bruce tilted his head. "You sound like you're feeling better."

Bucky took in a breath, then released it, feeling his brain settle down and start to unwind, a sort of mellow haze settling over his thoughts. "I think it's working."

"Can I take your pulse again?" Bruce asked. After Bucky had obliged him and fifteen seconds had passed while Bruce counted, he nodded once. "All right. You'll do better to not watch. I'm going to go ahead and take that blood now."

Steve spoke up when Bucky caught himself starting to watch Bruce pull on a new pair of gloves. "Hey, Bucky, over here." Once Bucky had turned his head to look at Steve, he noticed that Steve still had a hand on his metal arm. "Don't look, remember? Why don't you talk to me, huh? Or just listen. Just don't watch that, okay?"

"You don't need to talk," Bucky said. "I'm okay." He didn't say it, not with Tony and Bruce right there, but Steve had heard him say before that just focusing on Steve in general helped sometimes, because Steve was not back there, not part of Hydra, so if Steve was there in the present, then so was Bucky, and Hydra wasn't. It was odd logic, but it worked.

He felt the pinch of the needle and flinched slightly, but Steve tapping his finger on Bucky's leg kept him from turning his head to watch. Steve occasionally glanced over to see what Bruce was doing, but never let Bucky look away from him. "Looks like he's almost done," Steve said after what felt like it might've been awhile, but with how fast blood draws could actually go, it was probably only about thirty seconds.

"Not almost," Bruce said, and Bucky felt the strange sensation of the needle leaving his arm, and then the soft feeling of a cotton ball pressed against his skin. "Completely done."

By the time Bucky had turned his head to look at what Bruce was doing, the needle had already been deposited into a sharps container with a clatter, and Bruce was lifting the cotton ball and examining the skin. "No bleeding." He looked up at Bucky. "You did good. You can pull your sleeve back down."

Bucky gladly unrolled his sleeve, and looked at the damage he did to the counter. "Sorry about your counter."

"It's fine," Bruce said. "Better the counter than one of us." He paused. "Or a neighborhood in Manhattan."

"Or almost your girlfriend," Tony added. At the confused looks all three of the other men turned on him, he shrugged. "I was having a nightmare, accidentally called for the suit. It tried to attack Pepper because she was trying to wake me up and was perceived as a threat as a consequence. So relax, the counter's the least of our worries. You're not the only one who's been there, and you're not the only one who's had to have medicine because of it. Welcome to my prestigious club of Ativan takers."

"You still take it?" Bucky asked, wondering how long that Ativan would stick around in his system. He still felt a little weird.

Tony shrugged. "I still have my prescription. Don't use them that often anymore, but yeah, still keep 'em around. Pepper had to be on..." He trailed off, thinking. "Oh! Xanax. It's similar to what Bruce gave you, they're both benzodiazepines. She started on a pretty low dose, I don't think what she was on would even blip on your body's radar."

Bruce eyed Steve. "And if you think you need it, I can write a prescription for you, too."

Steve shook his head. "No, I think I'm fine. We're both usually pretty good at talking the other down. It's rare that we find such a strong trigger like this was." He eyed Bucky, like he was trying to decide if he should answer for Bucky or not.

"You don't need to look at me like that," Bucky said, still feeling rather vague. "How long does this stuff last?"

"About twelve to twenty-four hours in normal humans," Bruce said. "So about four hours at most for you. You might want to go ahead and just nap it off."

Bucky made a noise that was meant to be a 'meh' and ended up sounding more like a broken squeak toy. "Oh boy, a sleeping pill. How do people on this stuff handle this?"

"We sleep a lot," Tony said. "But no, really, this is why you don't usually start on a high dose. I was on half of what you took."

Bucky looked at him for a long five seconds. "Did it make you feel this vague, too?"

Tony grinned. "It certainly made it so my thoughts weren't racing around so much. Sleep it off, you'll feel better."

Steve looked past Bucky at Bruce. "How long before we get results?"

Bruce glanced at the blood samples. "It usually takes about five to seven days, but I can have it in about seventy-two hours, if you guys think it's important enough. But after putting it off for a few weeks, I think we can wait the five days. I do have other things I have to do around here, after all."

"That's fine," Steve said. "We're not in a particular hurry." He looked at Bucky. "We should get you home so you don't fall asleep sitting up there."

"Will not," Bucky protested, then shooed away Steve's hand when it was offered to help Bucky down. "Not a damsel in distress here, Steve." He slid off the counter more than hopped off it, and glanced at the damaged edge. "How can I help repair that?"

"Don't worry about it," Bruce said. "Just go home and rest. Doctor's orders."

Bucky gave him a half-hearted salute, waved to Tony, then headed out, quibbling at Steve about who got to be in front this time. Bucky still didn't like not being where he could see Steve to make sure he wasn't being left behind, and Steve reminded him that he was currently drugged and would probably do well with someone to make sure he made it home okay. Bucky swore at him, but gave in when Steve compromised that they walk together, instead of trying to lead each other like mother hens.

He slept through lunch.

* * *

><p>It'd been four days, a day less than Bruce's projected five to seven window, but JARVIS's systems and the nice set up that Tony'd had made for him had shaved a bit of time off the DNA analysis.<p>

The first thing Bruce walked into his lab that morning, full of ideas for medicines to design to work on Steve and Bucky- their physiology was fascinating, as guilty as he felt for sometimes thinking of his friends as subjects -was the waiting report.

"Good morning, Doctor Banner," JARVIS greeted. "The DNA analysis on Mister Stark, Captain Rogers, and Mister Barnes is ready."

"Thank you, JARVIS," Bruce said, setting some notes he'd been working on down by his desk. His 'moonlighting' as a biochemist was becoming more of his day job, while radiation- something he was probably safer getting away from -was becoming more if an occasional side project. But, as with all of Bruce's jobs, he tended to take them home with him. Which left him carrying notebooks to his lab every morning.

One of these times, he'd listen to Tony and sit down with that XBox One that he'd gotten from his friend for Christmas and try to let his brain work in a different direction for awhile.

"Anything interesting in the analysis, JARVIS?" he asked, lifting his thermal mug of coffee to his lips.

"I'm afraid you may wish to call Mister Stark to assist you," JARVIS said. "My programming is insufficient to make any deductions based on the available information."

Bruce paused, his cup tilted just enough for the warm liquid to touch his lips, but not enough that he was committed to taking a drink just yet. He elected to lower the mug. "That weird?"

"No moreso than the samples you had analyzed of your own DNA," JARVIS said. "But there are different anomalies, particularly on Mister Barnes. I cannot make clear conclusions based on what is available to me."

Well, that sounded sufficiently ominous. He glanced at his computer display, the thin glass with touchscreen foil over it blank, not yet booted up for the day. He contemplated taking a look at that DNA himself, see if he couldn't figure out what was going on with it on his own. It wasn't like Tony was any sort of biology expert. But the extra big brain and good eyes might help.

Bruce took a deep breath. "JARVIS, please contact Tony if he's awake, ask him I would like his help down here. If he's not awake, I can wait. It's not an emergency."

Silence filled the lab, except for the sound of Bruce bringing his computer back to life for the day. The screen lit up, asking for a login. While it processed his retina scan, JARVIS spoke up again. "Mister Stark was just finishing breakfast, Doctor Banner. He says he will be in the lab within five minutes."

"Thanks."

Bruce had to resist the urge to open those DNA files before Tony got down to the lab. He had a feeling that if JARVIS was recommending he bring in someone who had no relative expertise in the field, he might want his hand held while he did it. So he sipped his coffee and waited.

Tony entered the lab about three minutes later, according to Bruce's watch. "Good morning, geek friend of mine!" Tony said, sounding probably a bit too chipper for that time of the morning.

Bruce didn't terribly mind. "Good morning, Tony. I don't suppose JARVIS said why I was interrupting your meal?"

"Not interrupting," Tony said. "And sorta. He said that the DNA results were in and they were weird."

Bruce doubted that was the exact word JARVIS used. "He told me I probably wanted to wait for your help. Apparently, weird is exactly what they are. Bucky's is the weirdest." He looked at his monitor, tapping at it, bringing up the files on the DNA results. "We'll look at yours first, just to get a base idea of what's normal."

"Me? Normal? You wound me," Tony said, yanking over another stool and sitting down next to Bruce to watch over his shoulder.

Bruce gave him a sidelong look of amusement as the file loaded. The image of Tony's DNA popped up, going through the normal motions of what DNA should do- replicating, repairing, dying, replaced by the replicated strand. "Okay, that's what we're supposed to see," Bruce said, then pulled up Steve's.

Tony headtilted. "It looks about the same."

"Mm." Bruce studied the DNA strands, the chromosomes and how the proteins and amino acids were reacting. "At first glance, it is," he said, tapping at the screen to get a different view. "There's mutations here and here, though. Looks like a base deletion shift. His DNA is replicating at a fantastic rate. His telomeres are also too long for a man his biological age. That's probably also a result of the replication rate. Nothing too unexpected, although I'd still love to know what was in that serum to cause that change."

"Let's look at Bucky's," Tony said. "JARVIS said that's the weird one."

Bruce minimized Steve's file and pulled up Bucky's.

He almost wheeled himself away from the computer when the image came on screen. "What the hell?"

Tony leaned back like the image might bite him if he got to close. "Whoa. Bruce, that doesn't even look human. Are you sure the process didn't do something weird?"

"I'm not," Bruce said, leaning in and tapping at the screen. "JARVIS, can we get a 3D display of this, please?"

"Yes, Doctor Banner," JARIVS said, producing a floating image in the middle of the room.

Bruce pushed his chair around Tony and grabbed the image of the twisted and malformed DNA and examined it from as many angles as possible. "It's definitely still human," he finally said. "It looks deformed because there's been double-helical breaks. JARVIS, animate this, please? Show me what's going on here."

He let go of the image and let it hang while JARVIS processed the new image specs. Bruce watched in fascination as the DNA formed, broke, was replicated faster than it broke, replaced, and started all over again. "His repair systems are moving at speeds that shouldn't be possible," he said, staring. "Not even cancer patients see this level of replication."

Tony wheeled over next to him. "Any idea why his is so weird compared to Cap's? They both ended with the same approximate effects."

Bruce rested his chin on his fist, watching the animation. "I might. JARVIS, can you bring up the Winter Soldier Project files, please? Just the sections on the chemicals used and their observed effects. The machines probably had nothing to do with this."

The DNA image minimized to one side by Tony and Steve's samples, and the translated copy of Hydra's files took its place. Bruce skimmed over the different phases, the chemicals listed, still wishing he could figure out what these chemicals _were._

"There," Tony said, pointing over Bruce's shoulder. "Phase Two results."

"That's what I was thinking," Bruce said. "The effect of that was permanent, it wasn't reversed or overwritten. There was just new information added to counter the damage."

"I'll go call them," Tony said, pushing himself across the room to the telepresence monitor. Bruce watched as the system activated, and then Bucky's face appeared on the screen. "You and Cap are both awake, right?" Tony asked.

Bucky instantly looked wary. "We are. You're calling from the lab and you open with that. Because that's the heart attack I wanted for breakfast."

"Get down here," Tony said. "Nobody's dying, but we have the DNA results and you're going to want to see this."

Bucky didn't look terribly happy to hear that, and then Steve's voice was heard from off-screen. Bucky turned his head. "Don't ask me," he said in response to whatever Steve had said. "Just go get dressed. You don't get to go down to the lab in lounge pants and fuzzy slippers."

"They're not fuzzy," Bruce heard Steve say, then Steve moved by the screen behind Bucky, waving tiredly at Tony on his way past.

"We'll be down in a couple minutes," Bucky said, then the line disconnected.

Tony pushed himself back over next to Bruce. "He's going to panic when he sees that, you know that, right?"

Bruce looked at him. "You think I should have another Ativan ready?"

Tony shook his head. "No, not that kind of panic. But he won't take it well. I'd give him the option of hearing the explanation or the seeing the image first."

Bruce made a noncommittal noise, pushing his chair back to the still-mangled counter so he could lean back against it. He eyed the damage. "We should get that fixed."

Tony wheeled to the other side of the projected image and glanced past it to see the counter. "I don't know, it gives the place a bit of character. A bit of history."

"Maybe," Bruce said. "But Bucky won't like coming down here and having to see it. A lot of people don't like seeing reminders of their weaknesses. Men like him even less so."

"Then we'll fix it," Tony said, somewhat dismissive. "JARVIS, get rid of this image for us, will ya?"

The image dissipated.

Bruce went back to the Hydra files, studying the chemicals and observed effects for the thousandth time, this time with new eyes. He couldn't believe how lucky Bucky had gotten after the Phase Two drugs had started to backfire. If Hydra hadn't had Phase Three ready, he would've been long-since dead.

He took a few seconds to breathe and rein his temper back in. Unless and until he found a Hydra base he could rip apart and not feel bad about it, he couldn't risk the other guy coming into play over this issue. Maybe he'd talk to Steve and Bucky about allowing him to tag along on one of their 'we hate Hydra' charity missions.

"You okay?" Tony's voice cut into his thoughts.

Bruce startled, looking up at him. "Yeah, why?"

Tony motioned to him. "You look like your blood pressure's raising. Remember, you promised, this building gets a 'no other guy' pass. We live here."

Bruce sighed, letting out some frustration with it. "I'm fine. I just-" He pointed at the files. "This gets to me, I suppose. Nobody deserves to go through what they did to him. And it upsets me even more now that he's a friend and not just someone who had bad things done to him."

Tony wheeled over by him and put a hand on his shoulder. "I know. And we're helpless to undo any of it. Not necessarily the physical results. Even with warped DNA like what he's got now, those changes are keeping him alive. But..." He tapped the side of his head. "This is the part nobody can fix."

Bruce didn't answer at first, then looked pointedly at the mangled counter edge. "Yeah, that's the part that bothers me."

Tony didn't respond to that except to pat his shoulder, before wheeling over to Bruce's desk and digging in the drawers for the blueberry snacks that he'd gotten Bruce addicted to.

Steve and Bucky arrived a few minutes later. Steve still looked a little tired, and the remark about him still being in his sleeping clothes before explained why. Bucky had pulled his hair back, and Bruce wasn't sure what had prompted that change. He'd only ever seen Bucky with his hair back once, and that was at the charity ball. Interesting detail to note.

Tony held out the bag to them. "Blueberry?"

Steve stared at the bag, then at Tony. "Do you eat _anything_ else?"

While Bruce had to smother a laugh, Bucky looked confused, which made it that much harder to smother that laugh.

"You've seen me eat other things," Tony protested, popping another blueberry snack into his mouth. "I've eaten hash browns, I've eaten lamb, I've eaten goose." Then he pointed at Bucky with the bag. "All very good, by the way. Blueberry?"

Bucky studied the bag a moment. "I think my nerves are going to want me to pass," he said, looking at the computer monitor with the Hydra files up.

"Probably," Bruce agreed, and he heard Tony go back to snacking, his hand rustling the plastic bag. "Okay." He looked at Bucky. "You have two options: one, we can show you the images of your DNA, and then explain what we think is going on, or two, you can listen to the explanations before the images. Take your pick."

Steve started studying Bucky, who was staring at the computer screen like it might make the decision for him. Finally, Steve spoke up, having apparently come to a decision for Bucky. "Let's do mine, first, assuming it's not too bad. I think the image first will be better. An explanation might not make sense without seeing what's being described."

"Wise choice," Bruce said, minimizing the Winter Soldier Project files and tapping on Steve's DNA file, pulling up the image. "JARVIS, a projection, please?" The active image of Steve's DNA filled the center of the room. "Yours looks almost normal," he said, getting up and walking up to the image. He grabbed hold of the DNA strand. "JARVIS, Tony's, please? For comparison?"

Tony's DNA joined Steve's in Bruce's other hand. "This is Tony's DNA. Completely normal, despite being Tony's."

"Hey!"

Bruce ignored Tony's interjection. "You have some changes here, in the lower part of the code, between the double helix." He let go of both images, pointing to the different pieces between Steve's helix. "You have what we call a base shift damage. Basically, some part of the original code got taken out. Normally, those changes don't amount to much, the DNA's repair systems will fix the damage, and the strand won't replicate with the changes. Sorta. That's simplifying it a lot."

"Damage?" Steve said. "I thought it was a mutation that the serum did."

"It was," Bruce said. "Mutation is a change in the base sequence of the DNA. In rapidly dividing cells, unrepaired damages to the DNA continue to replicate and become a mutation. I still couldn't begin to guess what was in the serum that did this, but basically, part of your original genetic code was removed by the serum, damaging the DNA, and then the Vitarays caused such rapid replication of the changed strand that the repair functions couldn't keep up, until everything had been rewritten and there was no copies of the original DNA to use to replace anything."

He pushed Tony's DNA to the side, letting it minimize back to the screen and out of the projection. "Your DNA is continuing to replicate at a higher rate than normal humans- that's expressed in your accelerated metabolism and your healing factor. If your metabolism hadn't jumped to the levels it had, your DNA would be replicating far too fast for the older cells and strands to break down, which is what leads to cancerous growths."

"Remind me to never be unhappy about always feeling hungry again," Steve said. "But the mutation's stable?"

Bruce nodded. "It is, barring something very odd. The original DNA's gone, there's nothing to revert back to. Just don't get into any chemicals or dangerous radiation to cause a new mutation to take hold." He dismissed the image of Steve's DNA and looked at Bucky. "Your turn. How do you want me to do this?"

Bucky didn't answer at first, looking where the image had been, then looked Bruce square in the eye. "Which way would you do it?"

"I prefer the 'jump into the cold water and get the shock over with' route, myself," Bruce said.

"Then show me the image."

Bruce braced himself for Bucky's reaction, and tapped the file with Bucky's DNA on his monitor. The malformed DNA appeared in the middle of the room.

Bucky turned an unhealthy shade of white and didn't look like he was breathing much. "What's wrong with it?" he asked, voice just a decibel or two above a whisper. Steve put a hand on his shoulder, apparently unmindful of the fact that it was Bucky's metal shoulder.

Bruce took the projected image of the DNA and turned it to show off the breaks. "See that? Those are double helical breaks. Essentially, the backbones of your DNA were snapped. Normally, you shouldn't be able to function with that sort of thing happening, double helical breaks are the worst things that can happen to your DNA. But, if you watch what's going on here..."

He let go of the image, letting JARVIS animate it. "You'll see that the DNA is replicating before it's breaking, and it's doing it at an astronomical rate. Both you and Steve have an advanced replication rate, but yours is far and above his. My theory is that the Phase Two chemicals used that caused the observed damage is what is causing your DNA to shatter like that not long after initial replication. The Phase Three drugs countered it by accelerating the replication rate to keep up with the enhancements they wanted you to have without falling behind the damage rate."

Bruce adjusted his glasses, watching Bucky stare at the DNA and half-wondering if Bucky even heard him. "The fact that they had the Phase Three drugs ready tells me that if Phase Two hadn't failed, you would've died from what essentially would be cancer. The replication rate only works as it is now because of the botched Phase Two drugs."

Bucky was still too pale, breathing too shallow, and Bruce braced himself to have to come up with some sort of on the spot treatment that would help Bucky get through the oncoming anxiety attack. He rather wished he'd taken some courses in psychiatry, between Tony, Pepper, and now Steve and Bucky both.

A muscle in Bucky's cheek twitched, and his jaw clenched. "Is it stable?" he finally asked, voice only a bit stronger than it had been before.

"As long as the repair and breakage keep occurring at this rate, yes," Bruce said. He watched Bucky nod, watched his right hand start to shake ever so slightly.

When no further response was forthcoming, Bruce pulled up Steve's DNA again. "One more thing you two might find interesting is the telomeres on the ends of your chromosomes." He pointed to the ends. "See how long these are? They're too long for men of your biological age. Telomeres will break down and get shorter with each replication and division of your DNA. That's the biggest cause of aging. With your high replication rates, they're not shortening like they should be. I know a large part of the reason you two are still biologically thirty despite your calendar age is the decades of freezing, but I suspect you'd biologically be far younger than your calendar age even if you hadn't gone under ice. You're not aging, or if you are, very slowly. So you two will be around for awhile."

Steve and Bucky exchanged a look, one that Bruce couldn't entirely read, but he had a feeling it said a lot between them, before Steve looked back at Bruce. "How long?"

Bruce shrugged. "I honestly couldn't say, Cap. It could add only another twenty, thirty years, or it might be a lot longer than that. I doubt you'll live the several billion years it'll take for the sun to enter its red giant phase, though." The fact that life on Earth would cease to be a few billion years before the red giant phase _actually_ began was beside the point.

"I should certainly hope not," Steve said with a frown.

"Who hasn't eaten breakfast?" Bucky asked, making Bruce's brain do an abrupt left turn with the conversation.

"I did," Tony said, "but if you're making those fabulous hash browns again, I may have to pop in for a bite or two."

When Bucky's expectant gaze turned on Bruce, Bruce shrugged. "I had a bagel and some coffee. That probably doesn't count, does it?"

Bucky shook his head. "Not by a long shot. Come on, I'll make you a real breakfast. Put that shit away." He waved at the DNA images.

Deciding that Bucky was probably doing what he was as a coping technique, Bruce decided to oblige him and shut down the files. "I won't turn down proper food, I suppose."

"Good, come on, we just went grocery shopping yesterday, I have plenty of everything." He looked at Tony. "You know, you are going to gain a lot of weight if you keep eating a second breakfast with us."

"I'm a hobbit," Tony said, standing up and putting the blueberry snacks away in the desk drawer. "Don't worry, I don't do it often, although I'm going to start waiting an extra hour on breakfast to make sure I'm not getting an invite first."

Bruce grabbed his cooling cup of coffee, took one last swig of it, and set the empty mug on his desk. "I don't suppose you two have coffee, do you?"

"We have tea and cocoa," Steve said.

"Tea's fine," Bruce said, then followed his friends out.

* * *

><p>Bucky knew that sneaking out of the apartment late at night was difficult at best, with Steve's light sleeping, so he left a note, saying he'd gone for a walk in the building, and if Steve got worried, too damn bad. Bucky'd be home when he got home.<p>

He knew that sneaking into Bruce's lab might not be possible, if he couldn't get JARVIS on his side. There wasn't an emergency ward, per se, in the medical center; the doctors who worked there were all on-call only, there for Stark Industries employees, and with no current patients who needed overnight care, nobody was there. The med center was darkened, only the bare minimum of lights on.

Bucky navigated his way through the twists and turns and the labs and the hallways with exam rooms he made a point of not looking into. Meaning no offense to Bruce, Bucky hated doctors, was very grateful he hadn't needed the care of one yet. But, he supposed, if he had to be treated by one, Bruce was the only one he'd trust. And even that was difficult to give, if the humiliating display from less than a week ago was any indication.

He came to the secured doors and looked at them, looking for a place to type in a passcode, or a retinal scan, or a fingerprint scan, or _something,_ but he saw none. Feeling frustrated, he tried giving the doors a push. He could open them against their will with his strength, he decided, but that might trip an alarm, with the resistance they were giving at his light contact. He sighed. "JARVIS, help a guy out here," he said quietly.

"I'm sorry, sir," JARVIS replied. "But the medical laboratory is closed."

Bucky blew out a huff of air. "JARVIS, please don't make me have snuck out for nothing."

JARVIS didn't answer right away, but the doors clicked and opened. Bucky offered the AI a thank you, and continued down the hall, another turn, then to Bruce's lab. The door had a standard old lock, probably something more to Bruce's comfort than what Tony would normally have. They were both high-tech geniuses, but Bruce seemed the sort to enjoy an old fashioned door lock and key.

Locks like that weren't hard to open, not for him. So, in he went.

The lab was quiet and empty, lit only by the light from the window. Bucky examined the computer monitor, the thin glass with touchscreen film, and realized he'd just bumped into a problem.

He had no damn idea how to log in to the wretched thing.

With a hopeless sigh, he hopped up on the counter, crossing his legs underneath him. The damaged edge was just in his sight, and he reached down and tried to unbend the metal.

It almost looked okay when he heard footsteps. He decided that at that time of night, where he was, it was one of three people: Steve, Tony, or Bruce. At that moment, he didn't care which, because it didn't matter. He hadn't come down for any other reason than to brood and he knew it, would have to admit it.

It was Bruce that appeared in the doorway, wearing a pair of sweat pants and a loose, long-sleeved shirt. His sleep wear, Bucky assumed. "JARVIS told me you'd come down here," he said, not entering yet.

Bucky studied him for a few seconds, trying to decide why Bruce was keeping his distance. "Relax, I'm not going to destroy another counter or anything," he said.

That seemed to satisfy Bruce, seemed to be enough to let Bruce know that he wasn't walking into a potentially stressful situation without back up from Steve and/or Tony. "Mind if I ask what's troubling you?" he asked, walking over.

Bucky didn't look at him, looking down at the floor. "I'm down here instead of in my own apartment, and you're asking that?"

"Mm." Bruce leaned back against the counter beside him. Silence ticked by. "That DNA is still human, you know."

Bucky spared him a glance before focusing on the floor again. "Didn't look like it."

"It's mutated," Bruce admitted. "But so is mine. So is Steve's. Our DNA all looks a little different from normal humans. But we're still human."

Bucky snorted. "A little different?"

Bruce shrugged. "Yours maybe a little moreso than than ours, but that's only because of the breakage. The bases are still human."

Bucky couldn't manage more than a vague noise in response.

"Is that what's really on your mind?" Bruce asked after more silence had gone by.

Bucky couldn't help the derisive smile. "When did I get to be so readable, huh?" Then he took in a deep breath. "That was a lot of it. Sometimes I think about what I'm able to do that I shouldn't be, and it's kinda frightening. I got used to Steve being able to do those things, but they were weird, not scary." He paused. "Well, when he'd jump several stories, it'd make my heart stop, but not the way it is to do those things and realize that you're not a normal human anymore."

Bruce smiled. "I understand." He moved away from the counter just enough to hop back up on it next to Bucky. "You're not alone in being an odd one out. I have to watch my temper, or else I start destroying entire neighborhoods, and there's usually casualties."

Bucky folded his hands in his lap to keep his left index finger from trying to tap on something. "Do you have a choice with those casualties?"

Bruce shook his head. "Not much of one, not once I'm past that point. I try to be careful, but... the other guy doesn't always listen to reason. I think he tries- give him a good target and he sticks to it, but solid reasoning isn't his strong suit." Then he tilted his head. "But that's not what's on your mind. You dodged my question."

"You're all annoying," Bucky grumbled, completely without any heat. "Steve and Tony like to do that to me, too."

"That's because we're your friends," Bruce said. "We want to help you."

Bucky twisted his fingers together. "Too bad the only one of you that's going to be around is Steve."

"And there's what's bothering you," Bruce said.

Well, hell. He was already talking, and Bruce was right, he only wanted to help, so Bucky figured he may as well keep swimming. "When I woke up from Hydra's brainwashing, I started remembering the world I'd been raised in. Watching the world change every few years out of cryo didn't bother me much. It was just another thing that happened. But when it was _me,_ it was like falling asleep and dreaming, only it was the other way around. Everything I'd known was gone, like it'd never existed. The only thing left was Steve. Peggy was there, but I only saw her once before she died, and I couldn't quite believe that she was Peggy. She'd been a young woman when I'd last seen her, not an old woman going senile. And Peter'd been twelve the last I saw him. A kid. Now he's an old man, and he won't be around much longer, either."

He looked up from his hands, but not at Bruce. "And now I find out I get to watch what family I've established in this time grow old and die long before me. I'm not sure which way is worse- waking up suddenly to find everything gone, or watching it slip away and not being able to do anything abut it."

Out of the corner of his eye, he saw Bruce nodding vaguely, like he was considering Bucky's words and how to answer them. "If it makes you feel any better, you'll have me around," Bruce said. When Bucky looked at him, Bruce leaned back a bit. "My telomeres are artificially lengthened, too. And at least you have an out of being able to shoot yourself in the head. I tried once. Other guy spit out the bullet." He turned his head to make eye contact with Bucky. "So you and Steve won't be alone on this."

Bucky smiled faintly. "Would you be upset if I said 'good'? Because losing all of you didn't sound too great to me."

"Not at all," Bruce said. "I'm rather glad to have you two on board this crazy train myself. We'll all get to annoy each other to death. Now." He gave Bucky a stern stare over his glasses. "Go back to your apartment and get some sleep. Don't make me drug you again."

Bucky laughed. "That shit was terrible. I'll remember to spit it out the next time you make me take it." He hopped down. "Steve's probably worrying himself bald anyway. Thanks, Bruce."

Bruce slid off the counter and put his hand on Bucky's flesh shoulder. "Don't worry about it. We all need a listening ear sometimes. Go get sleep."

Bucky patted Bruce's hand with his metal one, then headed out of the lab, feeling a bit better than he had when he got down there.


End file.
